gemini 3.5 flash unusable

[gregist]

Opencode failed to send message with error: Requested entity was not found.

whereas Gemini 3.1 Pro Preview works fine.

[tejo]

I suspect that gemini-3.5-flash isn't available in Gemini Code Assist yet. The plugin routes requests through Code Assist rather than the public Gemini API, so I don't think it's an opencode-gemini-auth issue. It works if you use it with an API key (which hits the public API directly), so you can most likely select it from opencode because of that.

Just noticed that Gemini 3.5 Flash is only supported in antigravity cli that replaced gemini cli, I'm afraid that flash 3.5 support will never come to code assist...

[AceRothstein71]

how is banning with this going ? I been banned twice but need gemini for another vision/eye on code

[ox2842fc]

gemini cli has been updated the model list including gemini-3.5-flash.

But we cannot use it via opencode with this plugin. the error message is:

In opencode.json, we use google/gemini-3.5-flash as model:

    "error": {
      "name": "APIError",
      "data": {
        "message": "Requested entity was not found.",
        "statusCode": 404,
        "isRetryable": false,
        "responseHeaders": {
          "alt-svc": "h3=\":443\"; ma=2592000,h3-29=\":443\"; ma=2592000",
          "content-length": "114",
          "content-type": "text/event-stream",
          "date": "Thu, 11 Jun 2026 03:09:36 GMT",
          "server": "ESF",
          "server-timing": "gfet4t7; dur=688",
          "vary": "Origin, X-Origin, Referer",
          "x-cloudaicompanion-trace-id": "...",
          "x-content-type-options": "nosniff",
          "x-frame-options": "SAMEORIGIN",
          "x-xss-protection": "0"
        },
        "responseBody": "{\n  \"error\": {\n    \"code\": 404,\n    \"message\": \"Requested entity was not found.\",\n    \"status\": \"NOT_FOUND\"\n  }\n}\n",
        "metadata": {
          "url": "https://generativelanguage.googleapis.com/v1beta/models/gemini-3.5-flash:streamGenerateContent?alt=sse"
        }
      }

We tested google/gemini-3-flash-preview still able to use but 3.5 cannot.

[anthonyhaussman]

I have created a plugin inspired by opencode-gemini-auth that utilizes the Google AntiGravity API (via the Google Cloud Code Developer Assistance endpoints):
https://github.com/anthonyhaussman/opencode-agy-auth

It is still a very young project and certainly far from perfect, but it works well for my current use case.
Notably, it allows you to use Gemini 3.5 models, as well as Claude Sonnet/Opus models via an AntiGravity account.

[ox2842fc]

https://github.com/google-gemini/gemini-cli/blob/be7ba2c22adf095880b81da26f1afcc48520eebc/packages/core/src/config/models.ts#L70

google backend use google/gemini-3-flash as alternative name in certain instances.

update opencode.json to use google/gemini-3-flash can access 3.5 flash